SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e8549865a176f5a67b3b16e15e9fd350f4116d0b8bcae5938f22fe0de8231f2' 
  AND token = 'nJyLGKCifyyXiPVaIYoHC2h3Fns+elUvTxLjuUaZhcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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