SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd719909ccdc314b12ee6454fc4a588b2c8b725ff5f1b076947fb9956868ddeac' 
  AND token = '4VnuiGU36sJAoh+BkccyJYQCd/wjfzpGWjqI05L8eRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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