SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0155196752ab54bdfb068c44dfcd24b14a212fe99a82b7113d054290baf50c6e' 
  AND token = 'hMOfLrhXbf+vhm+drWchZcULfoB7cUIKBVo1KrS5VpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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