SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84bfeeda4e3b3b1261c33f2c9b1412527093a12c0991090a1c0af65514150f0e' 
  AND token = '2v8qJHGVVfNPEBdiB/GcNw3vnU25TrA05GTJCn0bm1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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