SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '918aa1e1cf3d894685b3ba83c4c0b74ad022448cc9e10947c6dbc74ff1092c1c' 
  AND token = 'rO4WQLRGxp/6LJGyfUOV3ZItzJsnAr50/QB5N2+kYEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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