SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b47e4d58a856628d5b4516613bce9b98a62538324dc6e4b7650de6d69423e202' 
  AND token = 'qI6AknAWyZNxWiXrl0WPrjJw9xwWUP+G4DjDZkLIPXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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