SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caf38bba24da650b7e045ac7b7b456075aa9a24c62b9a24ce27d8cad640ff173' 
  AND token = 'hpa3fSGjhrGg5j89KMNvFSZSHqbLdAY8kxBQCHRTXRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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