SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f7177f9d4048a6fbb6fae9ce73be2226e1b718d05c73577ab93492373487e29' 
  AND token = 'E3UYC9WnntsZGfu/UVh3kUT2ovBmGjTnEznyXiWtJOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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