SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adc8d243d9040b85147682f39da4cb911a2fb83bd4ce37cfc5ac90e9fe50a6dd' 
  AND token = '5xVk/R2xLRMHnLpKhNsjf8DUGqzlgVYslvJ25PrDmZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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