SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '504ff3b7077515a4a8531ca104dfa717946c6c89d93d5216d67f49182b441114' 
  AND token = 'fLp8SIWaCNYi0ugbkYNlKlxTwAHJz4z+9xPZviAZjAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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