SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88d6ff069e91c6c52c88f3c12bc695aaa2ef0300df61aa822c12aaee3c8ca10b' 
  AND token = 'z2HuzydjQEoi6MjRT4YYahTgsEzsTynLz4J+FHSQp8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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