SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0231f665f2f0be31c40dc369aeb513948cdab89c4a404ef055b8dfe99d2b2628' 
  AND token = 'm4jWm4sZ73qvBgNW7VL87XHeYcCKhW9aepF/kUCsPs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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