SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad2a2d6c8f5f8e951643e460dad4ff2ad29f04bdae25ae12167cd777756434a3' 
  AND token = 'npXVmcGTUzHjcJgmf0ujPh6p6JRo+8X531aSUd1kL+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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