SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3b0962f75fe5ef3e83167414a3147e07f6d97edf16d88eb3d81a0a1d7ac1236' 
  AND token = 'pHdjC7Dd45MRUKuzVTtOWMXjqgzYrKQee7GgHxQ2WJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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