SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef2ab811a6c3794c1b2dd82c27144f6db5d7749023e61bce7dbf852d801bfbb5' 
  AND token = 'MzjJ5+WPaKJKWa5BNcYPaxQt031zOgCZGlH1xVscpDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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