SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec6debca3e3b16d915a14bacba8be8560b10d56987aabbe0c998fcb638e0a018' 
  AND token = '58L+Y/+E1QMEv8dDKJWdsNsk+A2ib0jOMQV4r+kCxbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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