SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0b483e066371cdc11f88524eedaf45cbed8fe69d0f9373196125061c6a0b3b4' 
  AND token = 'edZRoNLaQILsmnvlu2in80wj/5EkywCsKz0YWmra8u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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