SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13a7901594680794c315ea227386a9eab5e7d66a915d65b790d722dbbc4900dc' 
  AND token = 'ult59vmegF1oIuxOjTPIq7fcD9vAnzaSukifeB89uXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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