SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e094418d452e470b27498ec80e1faaaee345a34bf975ead8f9cdaf3cbd1006' 
  AND token = 'eNiMDwTgg+f2hLw80l3WFg4X18eLkoRx7NlZZSQ0wEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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