SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d3cc83dd8b118b80fd4abafe7f5a484009278089c6e649a61b9856d672c2ea' 
  AND token = 'mwhGH+mcyJ/Y6Q72Uud+npxasFBY7cUk42uFwzvkzfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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