SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f4269a8b3d7410f2f618bf39001114e44227064b51434114387728b0fc35296' 
  AND token = 'BPey/RLx2Ic/CtaAsrwGg2aLM6atdOMopVt4gYXKG9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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