SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0537e3cfebfea1bf24b5c31afba391d72eb99afcad9e195a6e6230804422b6e1' 
  AND token = 'F7toOm38R96zfKSdrEfnkAYEXKyQlC+0T7REu9VJwkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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