SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4564e0a984c83b1e86ba6679c539d38aee1f1500e87adee71e40d1f2b32585a0' 
  AND token = 'Q7Y3j9SruieOJGUYhfaT+6YaKL/slFAFtn/0fhzqADg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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