SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '117289689eb2079d1840da314676641d480e192131ee9e076479212616fc3500' 
  AND token = 'wykb8SKVhz4f05kKJF7m+pH0SNuM6dUjfv2OkUbcwJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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