SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64ab2cc4399dd288271973b1955f60c9c07f1950b7e4935f044e2e113e37b888' 
  AND token = 'INW0LSLftJIBeJkntvVcgDzRIudZviNU/PNIO6wbxjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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