SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb6aed1877509276bed414db06f9e21bd93c3eb699bcf67f50c030885d96f25b' 
  AND token = 'cTYfn7Z+0FLbaW1LbAPro70NXW3K2S353rDCUShudFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}