SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c18168f5f2788a83c2b8916e1a2a31c8d54dbc76476dd1fb39a4c9ab3b2c1fb4' 
  AND token = 'ryEvRVhlADRmqTEJZQDCYJpMrUXAfKvtrdmlBYDPih4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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