SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe08a17ee0aa210805fcc14557d517ba94b25e36e0b32ec9e7e6166a895a4d0e' 
  AND token = 'nXRQMzqXdzxu2e+UdysVQtSoKhGfZ1k6MhUrGrjDbS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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