SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08b2a1081eaa140faccb7279a60aec4ae8b80922e01b93d7591ea5ce12611f76' 
  AND token = 'ttp+lQnMc6Jv2aKxZRXOIL8XoRB7luzh4av3QAUTRjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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