SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eabd9a3addacb8e3ea73719c93d24accf47c21163de8b12a98172f0141d79b58' 
  AND token = '5QXJsRaqTxsCRnCROe+BKjrGLFj+hT7lkmEl6GTu/Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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