SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a55cc297c7280e06f6df4162febeb8e7efa56e0e9533a2cc153db8d35d6adc4' 
  AND token = '1jWGQXG4sQ3J6L97PMGhmIJ2DT34w5aMFuGctnN1EX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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