SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c951903b518ce44613545c1ae1a0babedbe02354265d1493959b6fa56b9e4a9' 
  AND token = 'pHiB4ekImJ9tdQiFxOTazyCrzXCykJLHtHGr4l/4T7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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