SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f8e16501bbe4b17322cb64944d809bfc4c84c3b9e31c80cb3d70bf8ef85461b' 
  AND token = 'grkbiAK6wEajnS0vJwzrnDY/YX8PMLliHPlfLSwJD4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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