SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e235bcff1a5161161a7ea3b9802f5221ddc24394327cd60f12eeb9a54188eb94' 
  AND token = 'MzyqqpPqwfXW0D80zDQ9LhKhl9V2+Hc05hiXqDhHBEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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