SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5183174de40ac20809e5ec177fda845bac15c37cb5cf7e23b84649ae4b498726' 
  AND token = 'a1mrU0M91yRQDjIlmoQc+9l026gZmzoVoFoEEyEz/T8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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