SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04601293b33fa83db52e8e22a82bf670e313847f3029745e6454d606066b53bf' 
  AND token = 'ymlr/r2OJGf3SstiinlVF72nJ7rRQ0xS0G7rIuld2bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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