SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd99e0d36636979c3648a06fa047cf12ed3163f18017cbcdd4025708cc067e0d8' 
  AND token = 'EznKZ0/Hqw57KXfq3PTo2Zd6huEeAHFmDZ6o0XHvGHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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