SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8c950fb74d9fb341036945329689efc91f06c815bccf6d7738dc2bbc76f9328' 
  AND token = 'wb1VJo+zko0mWpEwjnknJsCn/9EyGjhQZT28qatn1Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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