SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09bc531d915139fd056213947f829ca599220f13ea8dbc5ee89353afa2bd03f' 
  AND token = 'tY1+BjlY2N+5t+VHHBLlqmrkSFn6uDbOGTWk5Kjwc9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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