SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0248270b03c61f5f0551acdff245782fbc47bb940af1c4f9438a909211297965' 
  AND token = 'NMTxKxjTL9tYtocuaXm67og9+eqZxR5cR7Kubx5CYyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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