SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc22f1d51bcb4cec244a92bb1298fe1436b737c1b49376f5998d81d39abe17be' 
  AND token = 'ZrUd1OHjVWBlqSH4UXUhWoxGnAYN+NPFl6Hbe8OtZU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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