SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd6d12f69c0920861f7e291e6c51ea35ad1451a582c3f319b6102bee51d306f81' 
  AND token = 'Pirp962I9EyJDwAxouqgHYF+x7bGtJkI9/DrBjRmzgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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