Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8ac9dc4e73065b63e79b4740e1a0cba3a5a7cdeeb6c87b843259d81d2a4a421' 
  AND token = 'HgLcKFsjsQf7ssBLDaFAb6VWahWBRhF9pmBwLyJOMXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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