SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba9fd5a515457ccc94a72d656301724ee607cee67e7d30aea1fb2c4e92dd0a4' 
  AND token = 'yCsJM5z2YrDrkhlI6+XwV7gyuZlhyG8eGu5Ij27FrDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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