SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4a8f0b225f67a5ef4c4cb866f9075d9aea5795d61a8094cebf879047a9c2f6a1' 
  AND token = 'eN1y4nnWDD+t8oGx6tehjp7OGwcwp9MZNOn60FBkjo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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