SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1265d04462c315d07bfd4579c676e0d01175f1d5ff111cdfabdbe988272ae817' 
  AND token = 'x5uqKbwkmzOHu1wUuQrbVaRJqQi3YKEhtCwdLjERSn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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