SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d5d3dfe2964f6403ef6690e63a056be8324f29f879154bb7192e2e0143d1616' 
  AND token = '0F2h1gob4BwjCrBQhLxDxU+J9NFe5KOXKHvVbcKRg3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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