SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8932bef1fec79dd35add5db1842bf01bff1b7a4e14e125a19725ba91bc52fa00' 
  AND token = 'Pr8BPEAWR2zrBDN2IDNUrsqmKVf/IWXnfdAzUhVaRj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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