SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01b4821418e807a2e85d66522337a22c7914bdd9061cce66d5d18119f89f493b' 
  AND token = 'IqnITzdTdPgtJAGEDyP85ohNIVrF3+tzPEBlDF/IURY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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