SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c4ae1a19db6127db38fc1232910eea5e57c807d2d4cb9d8f65b2b27e94c3e4f' 
  AND token = 'hRUHMuvwlmeRlAdM6dMjQJvmPB7l9DLMLjSMAvXiauU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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