SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b28abe060c217c9b30bbfc21276320c72f8ea858a9807521dcd910a86b1815' 
  AND token = 'dSQRvFlE9+yIU3NH4vcvrXXafaJwu+mz6UMVT1cHFFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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