SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4911a0d3ccb04c0801ad0b4ae3a1b3c456aed4106feeed428dd7d5374ffd8fe' 
  AND token = 'Yc6ibZYR6MmfzQGYAW4PfW07EXlwo4lkR8oJzUGaTrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}