SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bcceacbd08368bd61c5dce0fd520b0a943d89740f9c027406d8cd5461b89aa5' 
  AND token = '3HN0xw7xtJH4CEsGkxnJvfITWAFqzu5oo0UtuXpfZYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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