Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '850acb23dfc0f7cb31a3865141cd6f8a0dc614cc36998866e7ef31bfc9755e2a' 
  AND token = '4ZcWfnhzzPI/1UO0rPdXLfX6wJUCrO+nrvkXrZrpBHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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