SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3d01783c7fd6fbad89fc157d82b4498b523b09d51a7d25412ba75df8264da809' 
  AND token = 'Tt0jBf24X06ZumScTfGd2IA5SO9QpK40ZlIFPo0yAw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}