SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0549f9f00fbb51c23cf8620ff1f794a121b75f83aec081ec17b1f03eb3d7fe5' 
  AND token = '3OENEUV7ypeszsYURvqQbGoR9/fAWlI2Ol4gvSwfI7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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