SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d615cf84b69984868e51c6df2dbdd7e888ccb3faf3b92ae8dae0224c80742dc' 
  AND token = 'rqpaCegxP1ecblQx+rP9M8Ljy1PkrtLmfBIhq31wZVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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