SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77bfc1abff7ca89fa13e77f8ed1492db7f38addeace7b3e3f6a0ae9843780248' 
  AND token = 'ANrK1Kb4CDQr66W2oz7osdhwsOKsWnL7WCI3strR7F8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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