SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adc705c4a3036f5ddf987a2ae917c4b8b34a5f08365c6c805f12b0b632806a47' 
  AND token = 'cuqy9lpGv+RiFwG/W1nPSBbqAP0qYuFqjCjNxeuWrfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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