SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52e2fafe38a1176c788bbd5459d78ce7c31df7a28a425cb6142c6a5b66f135d' 
  AND token = '/K7aENofmqHxjzhh7KwNgYxDcRuYuwJAtHI8osgVRfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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