SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf288bc57a22e970c09a3f596de735812d337415bdc12790a17d768cdcbcbfa' 
  AND token = 'J3jTGSxNFHd3xXyGI8sY5odZBow+Alxjwtv5I2TnPY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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