SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddfa710eb33b580458fbfe6c2d8883f95be4c21a383881123c889911c0c38466' 
  AND token = 'nKUayIaIivepgoz01pNo2tCr0MClaDF7V35Cwlr+AK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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