SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '691529989ccf7e993992e390b25bc974e54b72814e7d5df407ef5ace1ca96a47' 
  AND token = 'E8AOWpBokxhGkvv5cwlMoBSDKyhaDGx6jSXWGMsz0qk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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