SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d36378988109222752a978bd35903b3eed895f70a1511bc31abc519fbff458d' 
  AND token = 'FgJ0mZmDJJiSA8wuXUQhnzxzd4v3AASgJZnrbrFDyIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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