SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95ff6c28bd7a969f24be5fd54500addcb3770511bf0b8632239bde8a795cde07' 
  AND token = 'A6yM6jMgrmsyZcS69wGhg58iowgBho1tbwR8tsYtpss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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